Unable to back up containers on LVM over iSCSI

Original Publishing Date:
2022-04-13

Symptoms

Backup creation fails immediately for all containers with the following error:

    [root@mypvcserver log]# vzabackup localhost
    Starting backup operation for node 'mypvcserver.mydomain.com'...
    ...
    * Operation with the Container(s) srv.mydomain.com,#101,ns1.mydomain.com is finished with errors: Failed to start the file backup
    Acronis Error: Module=0 Code=0, Tag=0,.
    Backup operation for node 'mypvcserver.mydomain.com' failed: Failed to start the file backup
    Acronis Error: Module=0 Code=0, Tag=0,
    Backup failed

/vz volume is located on iSCSI partition:

[root@mypvcserver ~]# mount | grep vz | grep mapper
/dev/mapper/mypvcserver on /vz type ext3 (rw,_netdev,noatime)

The _netdev mount option tells us that the volume is located on an iSCSI drive.

Cause

The inability to backup containers, located on iSCSI volume, is recognized as a product bug with internal ID PVA-32618.

Resolution

Fixed permanently in PVA 4.6.4 Update 3 (release 4.6-1875).

As a workaround, it is possible to switch off snapshot creation:

Edit the PVA Agent configuration file:

~# vi /vz/pva/agent/etc/vzagent.conf

(or)

~# vi /var/opt/pva/agent/etc/vzagent.conf

Change the enable_snapshot value to 0:

vzlin_backup_serializer (for pre-PVA 4.6.4 nodes):

<vzlin_backup_serializer> 
<configuration> 
<backend>1</backend> 
<enable_snapshot>0</enable_snapshot>  <--------- !!!
<custom> 
<queue>0</queue> 
<heavy_timeout_limit>360000</heavy_timeout_limit>
</custom> 
</configuration> 
</vzlin_backup_serializer>

vzlin_backup_serializer11 (for PVA 4.6.4 and later):

<vzlin_backup_serializer11> 
<configuration> 
<backend>1</backend> 
<enable_snapshot>0</enable_snapshot>  <--------- !!!
<custom> 
<pool>0</pool> 
<queue>0</queue> 
<heavy_timeout_limit>360000</heavy_timeout_limit>
</custom> 
</configuration> 
</vzlin_backup_serializer11>

Restart PVA Agent:
```
~# pvaagent restart
```